The related art consists of films that provide oxygen barriers through the use of ethylene vinyl alcohol copolymer (EVOH), or polyamide meta-xylene diamine (nylon MXD6). These materials provide high oxygen barriers; however, their barrier properties are diminished when exposed to water.
Oxygen and moisture barriers are key properties to preserve food products. Thus, food packers employ the use of barrier films throughout the industry. Packages include liners, bags, pouches, and wrappers in a wide variety of sizes and construction. A sufficient amount of barrier material is used in the package to prevent the degradation of the product for the desired shelf life. However, barrier raw materials are more expensive than other polymers in the film structure, so only the required amount is used in the structure, which can result in a lack of strength.
U.S. Pat. No. 6,479,160 B1 provides examples of oxygen barrier films using different layers, and blends of polymers to achieve the required barrier level for packaging oxygen sensitive foods. Another example is U.S. Pat. No. 4,792,488, which provides a multilayer film using a layer of vinylidene chloride copolymer and a layer of ethylene vinyl alcohol copolymer. A third example is U.S. Pat. No. 4,770,944, which provides a polymeric structure with a barrier layer that is heated under moist conditions to improve the oxygen barrier and moisture penetration. However, the oxygen barrier and moisture barrier properties of these materials are lacking, such that there is a need for materials with improved oxygen barrier and moisture barrier properties. The materials provided herein are believed to meet this need.